Science News

When it is full, the reservoir, a few dozen miles from the Las Vegas Strip, reaches an elevation of more than 1,220 feet. But last week, Lake Mead broke records, falling to about 1,079 feet, lows not seen since the lake was created in the 1930s. At the moment, the lake is at only 38 percent of its capacity, and officials warn that the water level will continue to fall throughout the summer, with projections showing an estimated elevation of 1,073 feet by September.

More than 25 million years ago, India, once a separate island on a quickly sliding piece of the Earth’s crust, crashed into Asia. The two land masses are still colliding, pushed together at a speed of 1.5 to 2 inches a year. The forces have pushed up the highest mountains in the world, in the Himalayas, and have set off devastating earthquakes.

The vast amount of sea ice covering the Arctic fluctuates on a seasonal basis, and the winter peak marks a turning point before a melting period during the warmer spring and summer months. Arctic sea ice typically expands to a maximum in March and shrinks to a minimum in September each year. The National Snow & Ice Data Center said on Thursday that this year’s maximum occurred on Feb. 25, about two weeks earlier than the average, barring any unlikely additional growth of ice late in the season.

Droughts appear to be intensifying over much of the West and Southwest as a result of global warming. Over the past decade, droughts in some regions have rivaled the epic dry spells of the 1930s and 1950s. About 37 percent of the contiguous United States was in at least a moderate drought as of April 7.

Within the botanical menagerie that makes up the Amazon rainforest, which is so important it’s frequently dubbed the “lungs of the planet,” scientists have pinpointed a small number of tree species that are doing the heaviest breathing as they help to slow global warming.

Between 55 million and 40 million years ago, the northern edge of what is now India began to slam into the giant slab of Earth's crust that today carries Nepal and Tibet. This ancient collision had a terrible after-effect this past Saturday: The deadly earthquake, centered in Nepal, which had an estimated death toll of nearly 4,000 people as of Monday evening.